Health insurance high risk pools have been mentioned by President Trump and Congressional Republicans as a potential element of their Obamacare replacement plans, but they are not a new idea.  Past experience with high risk pools suggests that they can help to address issues of affordability, stability, and fairness in the individual health insurance market.  However, to do so, they must be adequately publicly subsidized and have benefit designs and cost-sharing structures that are comparable to health insurance products available on the open market.